Pile the greens on top; I recommend really piling them on since once you put them in the oven they wilt and decrease in volume. Plus - they are so good for you - the more the better.

Bake or broil in the oven until pita and hummus are warm, cheese is melted, and greens are wilted. (Watch it in the oven, though, especially if you broil ... if your green get too wilted and dry they will turn into kindle and flame! This hasn't happend to me, but it could happen, right?)